The invention relates generally to vibration isolation, and more particularly to a device for coupling an electric motor to a support structure and isolating the vibration of the electric motor from the support structure.
An electric motor is commonly used to power the fan in the heating, ventilation, and air-conditioning (HVAC) system of an automobile. The motor is typically retained in a motor housing assembly that is mounted to an air case. Various techniques have been employed to isolate the vibrations generated by the motor from the air case and the adjoining structure. For example, it has been known to use elastomeric grommets that surround the fasteners used to secure the motor housing assembly to the air case. It has also been known to make the motor housing assembly from a resilient, vibration-damping material.
When the motor housing assembly is made from more rigid materials, such as plastics, it has also been known to wrap or otherwise surround the circumference of the motor with a resilient band or shroud intended to isolate the motor from the motor housing assembly. When the motor is received in the motor housing assembly, the vibrations generated by the motor are dampened by the band or shroud and are not transmitted radially outwardly to the motor housing assembly. Other motor housing assemblies incorporate one or more damping pads located between an end of the motor and the motor housing.
Prior art motor housing assemblies are relatively expensive and have proven to be difficult to assemble and mount on the air case. For example, with some prior art designs, mounting holes in the motor must be painstakingly aligned with holes in the motor housing assembly and also with holes in one or more damping pads in order to secure the motor and damping pads in the motor housing assembly. Adhesives are typically required to secure the damping bands or shrouds to one or both of the motor or the motor housing. Additionally, the motor housing assembly typically includes two housing halves that must be carefully aligned with one another, brought together around the motor, and secured together at multiple locations to encase the motor. The housing halves often inhibit the proper cooling of the electric motor, which ultimately reduces the motor""s efficiency.
The present invention provides an improved vibration and noise isolation system for a motor. The motor housing assembly of the present invention is easy to assemble and is less expensive than prior art devices. Improved motor cooling is achieved without sacrificing the structural stability of the housing assembly.